Question 1

Which of the following best describes the role of the active site in an enzyme-catalyzed reaction, as illustrated in the first image?

Accepted Answer

It binds to the substrate and induces a fit that stresses specific bonds, lowering the activation energy required for the reaction.

Question 2

Based on the second image, what happens to the reaction rate when enzyme concentration increases while substrate is in excess?

Accepted Answer

The reaction rate increases linearly with enzyme concentration.

Question 3

Refer to the third image. What does the difference between the highest energy point and the energy of the reactants represent?

Accepted Answer

The activation energy ($$E_A) $$required for the reaction.

Question 4

Which part of the mitochondrion, as shown in the fourth image, is the primary site for the citric acid (Krebs) cycle?

Accepted Answer

Matrix

Question 5

In the fifth image, which process is responsible for the majority of ATP production during cellular respiration?

Accepted Answer

Oxidative phosphorylation

Question 6

According to the sixth image, what is the primary function of the electron transport chain in mitochondria?

Accepted Answer

To create a proton gradient across the inner mitochondrial membrane.

Question 7

Which of the following best explains why enzymes are considered highly specific catalysts?

Accepted Answer

Their active sites have unique shapes that only fit specific substrates.

Question 8

Which of the following statements about competitive inhibition is correct?

Accepted Answer

A competitive inhibitor binds to the active site, blocking substrate binding.

Question 9

During glycolysis, what are the net products generated from one molecule of glucose?

Accepted Answer

2 ATP, 2 NADH, and 2 pyruvate

Question 10

Which of the following equations correctly represents cellular respiration?

Accepted Answer

$$\mathrm{C}_6\mathrm{H}_{12}\mathrm{O}_6 + 6\ \mathrm{O}_2 ightarrow 6\ \mathrm{CO}_2 + 6\ \mathrm{H}_2\mathrm{O} + 	ext{energy}$$

Question 11

Which of the following best describes the relationship between photosynthesis and cellular respiration?

Accepted Answer

Photosynthesis stores energy in glucose, while cellular respiration releases energy from glucose.

Question 12

Which of the following is a correct description of substrate-level phosphorylation?

Accepted Answer

ATP is produced directly by transferring a phosphate group to ADP from a phosphorylated substrate.

Question 13

Which of the following is a product of the light reactions of photosynthesis that is used in the Calvin cycle?

Accepted Answer

NADPH

Question 14

What is the main function of the proton gradient established by the electron transport chain in mitochondria?

Accepted Answer

To drive the synthesis of ATP by ATP synthase

Question 15

Which of the following best explains why feedback inhibition is important in metabolic pathways?

Accepted Answer

It prevents the overaccumulation of end products by inhibiting an early enzyme in the pathway.

Question 16

Which pigment is primarily responsible for absorbing light energy during photosynthesis, and which colors does it absorb most efficiently?

Accepted Answer

Chlorophyll; red and blue

Question 17

During anaerobic respiration in muscle cells, what is the final product formed from pyruvate?

Accepted Answer

Lactic acid

Question 18

Which of the following best describes the induced fit model of enzyme function?

Accepted Answer

The enzyme changes shape slightly to better fit the substrate upon binding.

Question 19

Which of the following statements about oxidative phosphorylation is correct?

Accepted Answer

It uses the energy from electrons transferred through the electron transport chain to generate ATP.

Question 20

Which of the following is NOT a function of the mitochondrion?

Accepted Answer

Site of glycolysis

Cell Energetics: Enzymes, Cellular Respiration, and Photosynthesis

Study Guide - Practice Questions